Monster iguanodontoids

  

Pula, Istria, Croatia, late Albian (mid-Cretaceous)

About a 100 million years ago, the beaches near the city of Pula (which itself has about 3000 years long history) were sandy and muddy and the sea was shallow. The rudist clams formed some sort of rudist reefs not far from the coastal line. The stromatolites colonies were sticking out of the water, while the large sturgeon or/and guitar fish probed the mud for food swimming the shoals. Small, large and huge dinosaurs, crocks, monitor lizards and pterosaurs left their footprints in the wet sand and sticky mud.

  Many years later, the old beaches turned into multilayer limestone rock, looking like some sort of a giant book. The ancient archives with the notes of the the life long gone,waiting for the sea to uncover them and somebody interested and inquisitive to read the fossil "hieroglyphs".

Here are the pes footprints of the immensely large iguanodontoid. I am standing on the convex  left pes with infilling, while photographing the concave right pes (footprint) in an oblique view. My yellow outline marks the impression. The displacement rim is quite nicely visible, as well as the mud suction traces along the mid line. Each of the prints measure unbelievable 135-145 cm in length. I don't think there was a larger iguanodontoid print discovered anywhere in the world, so far. Yet, these prints are situated on one of the most popular and crowded beaches near Pula. I've stepped over these prints so many times myself over the years without noticing them. Why? Simply because they were so enormous, that they were too difficult to spot and figure out as once belonging to a living, breathing animal. The ornitischian who left them in the wet sand must have measured at least 18 to 20 meters in length! (See the comparative sizes in my banner)

Giant ankylosaurs

  Here are the pes footprints of the two giant ankylosaurs (not to scale) with my interpretations on the right:

Pula Albian (mid-Cretaceous) ankylosaur right pes lenght: 85-95 cm (A, B) - I am standing on it's toe #5 of it's four pes toes;

Tumbler Ridge (Canada) late Cretaceous anky has a scale of 10 cm for size comparison (about 44 cm total pes length) (E, F) Photo credit: Rich McCrea. 

 I know it sounds unbelievable, but the Pula ankylosaur, as derived from the size of the largest pes footprints (there are at least 6 of the foot impressions at the Pula site) must have measured some 14-16 meters in length (!)  In a way it wasn't that surprising to me, since all of the super mega fauna members from Pula site were world record holders. Check out my title banner: these are the ultra dinosaurs from Pula in scale (!) They were gregarious, as it seems from the fossil record. Maybe comprising of small family groups. A pair or more adult dinosaurs guarding and taking care of their offspring.
It is interesting that some members of  Thyreophora - a subgroup of the ornithischian dinosaurs
which include well-known suborders Ankylosauria and Stegosauria, had diverse number of toes.
While some of the ankylosaur ichnogenera had three, the others had four toes on their hind feet.
Thus it is possible to miss identify the thyreophoran three-toed pes tracks for iguanodontoid ones and vice versa, especially if the front feet impressions are missing or are poorly preserved. Despite of the enormous record size of the Pula, Istrian tracks it is less likely that these were artifacts.

The Tumbler Ridge site

Late Cenomanian theropod tracks

  Last year (2013) I finally visited the track site situated on an Istrian natural reserve park the cape "Kamenjak". There are Late Cretaceous (late Santonian) dinosaur tracks all over the place, but the best preserved are on the Grakalovac promontory, on the beach, near the entrance to the park.

A nice medium-sized theropod trackway is marked with ugly black circles (A). My interpretation (B). However, there are more theropod footprints scattered all around. See one in filled with the sediment (C) and my interpretation with a couple of more less preserved prints (D).
The larger tracks that nobody could identify so far, are also marked with black circle. They seem to me like the prints of a fairly large ankylosaur. More about it in the next post.


The Italian paleontologist Fabio Marco Dalla Vecchia wrote extensively on the dinosaur fossils in Istria. Here is one of the papers.

Ankylosaur tracks

 From 2010-2012 I have also discovered a few ankylosaur tracks near Pula. There were even possible baby ankylosaur prints. However, the most impressive are the giant pes footprints measuring some 75 cm in length. In the pictures below are a couple of nicely preserved ones, left by somewhat smaller individuals. However they were still large by any standards. Compare the tips of my shoes for size. The ankylosaur was probably similar to Polacanthus or Sauropelta. The upper images apparently represent the right pes, while the lower ones feature the left pes.

Compare to some of the footprints from Tumbler Ridge. See the Anky trackway
More tracks.

More on sauropod tracks

 In 2009 I have discovered one of the dinoturbated sites near Pula. Since that time, I managed researching several more similar sites along the beach there. In the picture is a suropod footprint (Brontopodus sp.) that was surprisingly well preserved in 3D. You probably remember playing in a wet sand as a kid. The sand had to be wet and of the precisely right consistence and you had to be very careful while making a cast of your plastic dish or it would have collapsed right away. The sauropod cast was originally a negative footprint, that served as a mold. It was filled in with the sediment ( wet rudistic sand) brought by a rising tide, after the original substrate containing the impression dried and hardened a bit. Both sediments were eventually buried under more sediments and lithified.

In recent times, the sea eroded off the upper sedimenst freeing the cast.

The mid-Cretaceous (late Albian) subadult sauropod (titanosaur) right hind footprint cast (positive) from the dinoturbated beach area, which is full of tourists in the Summer time (A).  The same print in false colours to enhance the shape (C). My interpretative drawing of the impression (D).

The negative of the left hind sauropod footprint, which was probably left by the same animal and was the part of the same trackway. The little black bag measures 13cm in length (B).

The adult animal had a foot that measured some 140 cm in length.

 

A sauropod right pes on a building block

 A sauropod right pes on a building block of the Early Cretaceous limestone at the pier near Pula (Istria, Croatia)

I don't remember if I said it before, but Istria has been literary "littered" with the Mesozoic fossils. The dinosaur tracks can be considered as numerous and omnipresent. Which doesn't mean they are easy to find by laymen. One has to learn distinguishing them from common artifacts. The limestone erosion is prone to forming very rich array of shapes.

So, here I am, walking along the beach and looking for some familiar shapes. I get awarded quite often. Here is a nice sauropod (probably a titanosaur) right hind foot print on a building block. The production process in the quarry left it in a rather good shape. Although, the block looks slightly "flawed" because of the dinosaur impression. The photograph was taken on February 15th 2014. Red outline helps you visualise the print. There is a low displacement rim in front of the track, where it should be. The pes measures about 60 cm in length, representing a decent size track maker sauropod. The largest sauropod hind footprints I've found there measure about 130-140 cm in length. Those were true giants! 

Finding dinosaur tracks on building blocks is not that rare either. I've found many myself. Some of the tracks were found by Dalla Vecchia, as described in his paper.

Nodosaur and possibly Rhabdodon finds in Quarry Stranice near Slovenske Konjice (repost from BDW 2005)

   

Mesozoic Mosaic pg #5

Illustration: Sauropelta - by Beri (graphite), Copyright © 2004-2005 Berislav Krzic

 

Mesozoic Mosaic pg #5
Photograph of Struthiosaurus austriacus (Bunzel 1870) fossil on display in Natural History Museum in Vienna Site: Muthmannsdorf near Wiener Neustadt, Austria Struthiosaurus might look like a cross between Edmontonia and Sauropelta, says Kenneth Carpenter, Ph.D. Struthiosaurus References s: (update 2014) Sympatry of two ankylosaurs (Hungarosaurus and cf. Struthiosaurus) in the Santonian of Hungary
Nodosaur and possibly Rhabdodon finds in Quarry Stranice near Slovenske Konjice   In the sediments of Quarry Stranice (kamnoloma Stranice) near SlovenskeKonjice (Campanian; gosauski razvoj) in north-east Slovenia, fossils of single and colonial corals were found. In addition to the corals, bivalves, fragments of sponges, snail shells, ostracodes, briozoa, algae and foraminifera were also found. On the west side of the site, near Lipa, fragments of fish teeth, a crocodylian tooth and the long bones of dinosaurs were discovered. These fossils were first found in 1999 by Franc Pajtler, and researched by Dr. Irena Debeljak. Dr. Debeljak (ZRC SAZU) thought the bones possibly belonged to a medium-sized quadrupedal plant-eating nodosaur, which was a member of the family Ankylosauria. This is the second discovery of dinosaurs in Slovenia. The first one, near Kozina, was in an area that was separated from Quarry Stranice in the Upper Cretaceous by the sea, precluding a comparison of the fauna from the two sites. The fossils of dinosaurs, crocodylians, turtles and freshwater fish indicate a rich vertebrate fauna at that time. The nearest site to Stranice with nodosaur remains is in the vicinity of Vienna (Muthmannsdorf -Wienerneustadt, Avstria). The locality of Quarry Stranice (kamnoloma Stranice) near Slovenske Konjice thus becomes an important palaeontological find. The fossils are on display in the Natural History Museum in Ljubljana: http://www2.pms-lj.si/oddelki/paleontologija/stranice.html English translation: Berislav Krzic Edited by: Brian Franczak Note (Feb/2014): as to my knowledge, up to this day, no further research has been conducted regarding the Quarry Stranice fossil finds.   .